It is made of stainless steel spring and can be bent freely without deformation. There are multiple options for cleaning the wool. The size and design is suitable for cleaning 9-35mm such as three- , four- , six- , eight- , one-inch water and other and glass of different diameters. Feature - Color: As shown. - Material: Stainless steel. - Size: Spring length 155cm filament diameter; 18/30mm. Type: Brush Brush material: nylon Shape: round Function: Cleaning Type: fish tank Handle material: 304 stainless steel Bristle length: 55 (mm) Brush use: cleaning water - Designed with rotating bristles and stainless steel, the flexible double- long brush can be reused many times for easy push-pull and pull. - Suitable for home and aquariums, our double-ended hose are flexible and suitable for use inside water , especially U-tubes. - Use a mild and warm water, keep the tube as straight as possible, gently handle the brush in a short stroke, and gradually work further in the tube. Avoid using large amounts of cleaning. - Two sizes of brush design, you can terminal according to your needs. - Warm Tip: Dear buyer, due to lighting effect, monitor’s brightness, manual measurement, etc., there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you! Package list: 2 x Brush